Well, my workflow for that is to implement that start->move->stop within a state machine.
Take a look at this example:
So as soon as the speed starts to increase, I change to my Start, when the start animation finishes, I blend into my Sprint state, and when the player stops pressing the movement button I then make a transition to play the stop animation.
One thing to be aware is that you may want to sync your animations, as they may have different lengths.
Take a look at Epics documentation about Sync groups
When dealing with sync groups, try to use sync marks to tell exactly how the animations are going to sync.
Take a look at Epic’s stream about Paragon’s animation techniques, it is really long but has some amazing knowledge to be absorbed there regarding to animation changes and syncs.
